Abstract. Rapid and ultrarapid opioid detoxification (ROD and UROD) centers promise quick, painless, same-day detoxification treatment for patients with opioid addiction. The goal of ROD and UROD is to provide a rapid transition from opioid dependency to oral naltrexone therapy. The patient is given general anesthesia and high-dose opioid antagonists. This induces a severe withdrawal but spares the patient the experience. In theory, the process is complete within four to five hours. The patient awakens without opioid dependency and is started on oral naltrexone. Any subsequent, persistent withdrawal symptoms are treated symptomatically. A novel, unapproved approach is to compound a pellet of naltrexone and implant it in the subcutaneous tissue. In theory, this should result in continuous therapeutic levels for this drug, and avoid issues with noncompliance. Case series: This article reports six cases of complications from the same detoxification center that performed UROD with naltrexone pellet implantation, including pulmonary edema, prolonged withdrawal, drug toxicity, withdrawal from cross-addiction to alcohol and benzodiazepines, variceal rupture, aspiration pneumonia, and death. Conclusions: The risks of this procedure are great and further studies should assess its safety and the novel use of naltrexone. Key words: opioids; heroin; addiction; detoxification; rapid detoxification; ultrarapid detoxification; naltrexone. ACADEMIC EMERGENCY MEDICINE 2002; 9:63-68 P ATIENTS with opioid addiction often struggle to achieve detoxification. Discontinuation of opioid use results in the severe discomfort of withdrawal. Many find methadone maintenance undesirable. For these patients, rapid and ultrarapid opioid detoxification (ROD and UROD) centers promise quick, painless, same-day detoxification treatment for patients with opioid addiction. This allows rapid transition from opioid dependency to oral naltrexone therapy. General anesthesia is given via endotracheal tube as well as highdose opioid antagonists. The induced withdrawal is complete within four to five hours and the patient awakens without opioid dependency. The patient is then started on oral naltrexone and any subsequent, persistent withdrawal symptoms are treated symptomatically. A novel, unapproved approach is to compound a pellet of naltrexone and